Recently, with the development of electronic industries and the advance of industrial technologies, various electronic devices are designed and produced toward small size, light weightiness and easy portability. Consequently, these electronic devices can be applied to mobile business, entertainment or leisure purposes whenever or wherever the users are. In these devices, probably the image-taking devices are most widely used as appeared in many kinds of fields, such as smart phones, wearable electronic devices or any other appropriate electronic apparatus. These imaging devices are attractive to daily applications for human because they are small and can be easily carried.
With the improvement of the living quality, people's demands on more functions of the imaging devices are progressively increased. In many circumstances people needs more flexible input/output medium for information transfer or exchange. The examples of media may be virtual keyboard or display by which spatial information is extracted, delivered or recognized via non-typical means. For example, many people are willing to acquire 3D images which can be contributed as a special methodology. Preferably, the 3D image contains accurate spatial information. Indeed, people may like to acquire the distance measuring functions in order to recognize hand gestures with the portable electronic devices. Normally, the spatial or depth information or the distance can be measured by a TOF (Time of Flight) measurement method or a dual camera distance measurement method.
As known, the measured result of the TOF measurement method has good accuracy. However, when the TOF measurement method is expanded to the planar scenario application or the multi-point scenario application, the software computing technology is very complicated and computational load is heavy. Moreover, the additional uses of the specified computing chip and integrated circuits (ICs) require lot of power consumption and high computing cost. Moreover, the TOF measurement method is readily affected by the ambient brightness. If the light pollution in the surroundings is serious, the accuracy of the measured result is low. On the other hand, the software computing technology for the dual camera distance measurement method is somewhat complicated and not easier. Moreover, since the dual camera distance measurement method uses two cameras, the dual camera distance measurement method are advantageous over the TOF measurement method in power consumption and computing cost. However, since the performance of measuring the distance from the smooth surface by the dual camera distance measurement method is inferior, the measured result about the distance from the smooth surface has lower accuracy.
Therefore, there is a need of providing a miniature spatial information capturing device capable of effectively acquiring a spatial distance information of a target object in a quick way.